<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
	</head>
	<body>
		<div id="div1" style="width:200px;background:red;height:200px;" ></div>
		<script>
			window.onload=function(){
				var div1=document.getElementById('div1');
				alert(css(div1,'width'));
				css(div1,'background','green');
			}
			function css(){
				if(arguments.length==2){
					return arguments[0].style[arguments[1]];
				}else if(arguments.length==3){
					//div1.style.background=green
					arguments[0].style[arguments[1]]=arguments[2];
				}else{
					alert("no")
				}
				
			}
			
			function css(obj,name,value){
				if(arguments.length==2){
					return obj.style[name];
				}else{
					obj.style[name]=value;
				}
			}
		</script>
	</body>
</html>
